AU2006318235B2

AU2006318235B2 - Combustion catalyst carriers and methods of using the same

Info

Publication number: AU2006318235B2
Application number: AU2006318235A
Authority: AU
Inventors: W. Wesley Parish; Michael D. Thompson
Original assignee: FEROX Inc
Current assignee: FEROX Inc
Priority date: 2005-11-18
Filing date: 2006-11-17
Publication date: 2011-05-12
Anticipated expiration: 2026-11-17
Also published as: CA2633438C; EP1954788B1; EP1954788A4; US7959693B2; WO2007062330A1; EP1954788A1; AU2006318235A1; US20080263940A1; CA2633438A1

Description

WO 2007/062330 PCT/US2006/061055 COMBUSTION CATALYST CARRIERS AND METHODS OF USING THE SAME TECHNICAL FIELD OF THE INVENTION 5 This invention relates to fuel soluble ferrocene compound compositions and methods of preparing the same. BACKGROUND OF THE INVENTION Increasingly, fuel sources are augmented with a variety of additives to 10 enhance many aspects of burning and combustion processes. Iron containing fuel additives have been found useful for such purposes. A problem frequently encountered in the addition of fuel additives is the difficulty in handling the additive before and during fuel supplementation. For example, iron containing fuel additives can be highly insoluble and fail to both produce the desired enhancement and cause 15 additional undesirable effects, such as fuel line occlusion. There is, therefore, a need for improved fuel additives. SUMMARY OF THE INVENTION The present invention is directed to compositions and methods for preparing 20 those compositions that can be more easily handled, improve an additive's solvation in fuel, and promote achieving the fuel additives' enhancement without occluding fuel lines. Such a composition can be rapidly soluble when added to a fuel or when fuel is added to a storage tank. Rapid solubility would promote homogenous blending of the iron containing fuel additive. A solid composition before dissolution 25 -can be advantageous over-liquid compositions for ease of application and storage. In a first aspect, a composition is disclosed comprising a fuel soluble ferrocene compound and a fuel soluble solid carrier. The fuel soluble ferrocene compound is selected from one or more compounds of the formula: Fe S R' WO 2007/062330 PCT/US2006/061055 where each of R and R' are independently selected from hydrogen, alkyl, cycloalkyl, aryl, alkylene, alkoxy, ketone, ester, aldehyde, amide, hydroxyalkyl, or heterocyclic. In some embodiments, the fuel soluble ferrocene compound is an unsubstituted ferrocene also known as dicyclopentyldienyliron. In some embodiments the fuel 5 soluble ferrocene is a substituted ferrocene, such as a bis-substituted ferrocene. In some embodiments, the composition comprises one or more additional fuel soluble ferrocene compounds. In some embodiments, the fuel soluble solid carrier is selected from one or more hydrocarbons, a single oxygen-bearing hydrocarbon, and mixtures thereof. In 10 some embodiments, the fuel soluble solid carrier is selected from one or more of biphenyl, 1-naphthol, 2-naphthol, diphenylmethane, hexadecanol, tritylalcohol, adamantane, triphenyl, p-tert-butylphenol, acenapthene, and mixtures thereof. In some embodiments, the fuel soluble solid carrier is selected from one or more of a single oxygen-bearing alcohol, ether, aldehyde, or ketone. In some embodiments, 15 the fuel soluble solid carrier is an aromatic hydrocarbon, such as biphenyl. In some embodiments, the fuel soluble solid carrier is a binary mixture of one or more hydrocarbons and a single oxygen-bearing hydrocarbon. In some embodiments, the fuel soluble solid carrier is a ternary mixture of one or more hydrocarbons and a single oxygen-bearing hydrocarbon, such as adamantine and an aromatic 20 hydrocarbon. Optionally, the compositions include a combustion additive. The compositions may be made into the form of a tablet. Advantageously, the compositions dissolve in a combustion fuel in less than 30 minutes. In some embodiments, the compositions dissolve in a combustion fuel in less than 10 25 minutes. In some embodiments, the compositions dissolve in a combustion fuel in less than 5 minutes. The compositions may be formulated to contain less than about 90% fuel soluble solid carrier. The compositions may be formulated to contain more than about 1% fuel soluble solid carrier. In some embodiments, the compositions may be 30 formulated to contain less than about 30% fuel soluble ferrocene compound. In some embodiments, the compositions may be formulated to contain more than about 2% fuel soluble ferrocene compound. 2 In another aspect, methods of preparing a fuel additive are disclosed, comprising combining a fuel soluble ferrocene compound and a fuel soluble solid carrier. The methods may optionally include the step of adding a second fuel soluble ferrocene compound to the composition fuel additive. The methods may optionally include the steps of melting the fuel soluble ferrocene 5 compound, melting the fuel soluble solid carrier, mixing the fuel soluble ferrocene compound and the fuel soluble solid carrier to form a mixture, cooling the mixture, forming a tablet, reducing the mixture to a desired particle size, and/or compressing the mixture into a tablet. In some embodiments, the cooling step is conducted in a shaped mold. In still another aspect, methods of supplementing a fuel are disclosed comprising adding a 10 fuel additive composition to the fuel, the fuel additive composition comprising a fuel soluble ferrocene compound and a fuel soluble solid carrier. In one aspect of the invention there is provided a composition comprising: (a) a fuel soluble ferrocene compound; and (b) a fuel soluble solid carrier which is biphenyl. 15 In another aspect of the invention there is provided a method of preparing a fuel additive comprising: combining a fuel soluble ferrocene compound and biphenyl. As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude other additives, components, integers or steps. 20 Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment, or any form of suggestion, that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. DETAILED DESCRIPTION OF THE INVENTION 25 Definitions As used herein, the term "lower alkyl" means a straight chain or branched alkyl group of from 1 to 6 carbon (CI-C 6 ) atoms, i.e., Ci, C 2 , C 3 , C 4 , C 5 , or C 6 . Examples include: methyl, ethyl, 1 propyl and 2-propyl, 1-butyl, 2-butyl, 2-methyl-l-propyl, 1,1-dimethylethyl, 1-pentyl, 2-pentyl, 3 pentyl, 2-methyl-l-butyl, 3-methyl-l-butyl, 2,2-dimethylpropyl, 1-hexyl, 2-hexyl, 3-hexyl, 2 3 methyl-1-pentyl, 3-methyl-i-pentyl, 4-methyl-1-pentyl, 3,3-dimethyl-1-butyl, 3,3-dimethyl-2-butyl, 2-ethyl-I-butyl, and the like. As used herein, the term "longer length alkyl" means a straight chain or branched alkyl group of from 7 to 12 (C 7

-C

1 2 ) carbon atoms, i.e., C 7 , C 8 , C9 C 1 o, C 11 , or C 1 2 . Examples include: C7 5 C 1 2 such as: 1-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 2-methyl-1-hexyl, 4-methyl-1-hexyl, 5-methyl-i hexyl, 1-octyl, 2-octyl, 3-octyl, 4-octyl, 6-methyl-1-heptyl, 5,5-dimethyl-1-hexyl, 2-ethyl-1-hexyl, 2-methyll-1-heptyl, 2-propyl-1-pentyl, 1-nonyl, 2-nonyl, 2-ethyl-2-methyl-1-hexyl, 4-methyl-1 octyl, 3,5,5-trimethyl-1-hexyl, 1-decyl, 2-decyl, 4-ethyl-1-octanyl, 2-methyl-1-nonyl, 4-methyl-i nonyl, 8-methyl-i -nonyl, 1 -undecyl (1 -hendecyl), 2-undecyl, 7 3A WO 2007/062330 PCT/US2006/061055 methyl-1-decyl, 1-dodecyl, 5-dodecyl, 2-butyl-1-octyl, 10-methyl-1-undecyl, and the like. As used herein, the term alkyll" means a straight chain or branched alkyl group of from I to 12 (C 1

-C

12 ) carbon atoms, i.e., C 1 , C 2 , C 3 , C 4 , C 5 , C 6 , C 7 , C 8 , C 9 , 5 Cio, Ci 1 , or C 12 . Examples include those provided for lower alkyl and longer length alkyl and the like. As used herein, the term "cycloalkyl" means a monocyclic or polycyclic hydrocarbyl group. Illustrative examples include cyclopropyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclobutyl, adamantyl, norpinanyl, decalinyl, norbomyl, 10 cyclohexyl, and cyclopentyl. Cycloalkyl groups may be unsubstituted or substituted. The term "aryl" means an aromatic carbocyclic ring having from 6 to 14 (C 6 C 14 ) carbon atoms, i.e., C 6 , C 7 , C 8 , C 9 , C 10 , C 11 , C 12 , C 13 , or C 14 . Illustrative examples of an aryl group or radical include phenyl, I-naphthyl, 2-naphthyl, 1 15 anthryl, 2-antrhyl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4 phenanthryl, 5-phenanthryl, and the like; including fused ring systems with rings that have less than 6 carbons such as 1 -acenaphthyl, 3-acenaphthyl, 4-acenaphthyl, 5-acenaphthyl, 1-azulyl, 2-azulyl, 4-azulyl, 5-azulyl, 6-azulyl and the like. Aryl groups may be unsubstituted or substituted. 20 As used herein, the term "alkoxy" means an alkyl group bonded to an oxygen atom where alkyl has the meaning as defined above. Representative examples of alkoxy groups include methoxy, ethoxy, tert-butoxy, propoxy, and isobutoxy and include the (C 1

-C

12 ) alkoxy groups, i.e., C 1 , C 2 , C 3 , C 4 , C 5 , C 6 , C 7 ,

C

8 , C 9 , C 10 , Cii, or C 1 2 . 25 As-used herein, -the term "acyl" or "ketone" -means a group derived from an organic acid (-COOH) by substituting the hydroxy group (-OH) with alkyl, cycloalkyl, and aryl where those terms have the meaning as defined above. Examples include C(=O)alkyl, C(=O)cycloalkyl, C(=O)aryl. As used herein, the term "ester" means a group derived from an organic acid 30 (-COOH) by substituting the hydroxy group (-OH) with alkoxy, where alkoxy has the meaning defined above. Examples include C(=0)Oalkyl, C(=0)Ocycloalkyl, C(=O)Oaryl, where alkyl, cycloalkyl, and aryl have the meanings defined above. 4 WO 2007/062330 PCT/US2006/061055 As used herein, the term "aldehyde" means a group derived from an organic acid (-COOH) by substituting the hydroxy group (-OH) with hydrogen. Examples include alkylC(=O)H, cycloalkylC(=O)H, arylC(=O)H, and C(=O)H, where alkyl, cycloalkyl, and aryl have the meanings defined above. 5 As used herein, the term "alkylamide" means a group such as, C(=0)NHalkyl, C(=O)NH(cycloalkyl), C(=O)NH(aryl), C(=O)N(alkyl)(akyl), C(=O)N(alkyl)(cycloalkyl), C(O)N(alkyl)(aryl), C(=O)N(cycloalkyl)(cycloalkyl), C(=O)N(cycloalkyl)(aryl), C(=O)N(aryl)(aryl), where alkyl, cycloalkyl, and aryl have the meanings defined above. 10 As used herein, the term "hydroxyalkyl" means an HO-alkyl-group or radical wherein alkyl has the meaning as defined above. As used herein, the term "heterocyclic" means a cyclic hydrocarbon with at least one carbon substituted with a heteroatom. Examples include pyrrole, pyridyl, furfuyl, and the like. 15 As used herein, the term "alkene" or "alkylene" means an alkyl radical or group with one unit of unsaturation between adjacent carbons (a carbon-carbon double bond) having from 2 to 12 (C 2

-C

1 2 ) carbon atoms, i.e., C 2 , C 3 , C 4 , C 5 , C 6 , C 7 ,

C

8 , C 9 , C 1 0 , Cu 1 , or C 12 , and includes, for example, ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 3-methyl-3-butenyl, 1-hexenyl, 2 20 hexenyl, 3-hexenyl, 3-heptenyl, 1-octenyl, 1-nonenyl, 1-decenyl, 1-undecenyl, 1 dodecenyl, and the like. As used herein, the term "fuel soluble ferrocene compound" means ferrocene (also called bis(cyclopentadienyl)iron or di(cyclopentadienyl)iron) and ferrocene derivatives. Examples include dicyclopentadienyliron, di(methylcyclo 25 pentadienyl)iron, di(ethylcyclopentadienyl)iron, methylferrocene, ethylferrocene, propylferrocene, isopropylferroccene, n-butylferrocene, dihexylferrocene, phenylferrocene, m-tolylferrocene, didecylferrocene, dicyclohexylferrocene, and dicyclopentylferrocene. Other examples include dialkylaminomethylferrocene. It should be understood that ferrocene is an organometallic compound consisting of 30 two cyclopentaidenyl rings bound on opposite sides of a central iron atom. Thus, different nomenclature systems will synonymously equate dicyclopentadienyliron and bis(cyclopentadienyl)iron with ferrocene. 5 WO 2007/062330 PCT/US2006/061055 As used herein, the term "fuel soluble solid carrier" means a substance used in association with a fuel soluble ferrocene compound to aid in the application of the fuel soluble ferrocene compound. The term also means a material that is a solid at or below a temperature of 40 'C (a solid with a melting point above 40 'C) in that a 5 one cubic inch of material will substantially sustain its shape under its own weight at 40 'C for a period of at least 24 hours. A fuel soluble solid carrier does not include polymeric materials, waxes, or paraffin waxes. As used herein, the term "tablet" and "tablets" means a mass of material of any shape and may synonymously include pellets, pills, grains, dosing units, balls, 10 spheres, cubes, and the like. As used herein, the term "combustion additives" means any ingredient added to affect the storage, preservation, and use of fuels such as cetane improvers, antioxidants, stabilizers, combustion improvers, emission reducers, and the like. As used herein, the term "hydrocarbon" means any aliphatic including alkyl, 15 cycloalkyl, aryls, heteroaryl, whether branched or unbranched as well as linear and branched alkenes, cycloalkenes, and arylalkenes. In accordance with this invention, the effectiveness of fuel soluble ferrocene compounds is improved by formulating a composition to include a fuel soluble ferrocene compound and a fuel soluble solid carrier. The invention also includes 20 processes for preparing a tablet form of a fuel soluble ferrocene compound for combining with various fuels such as gasoline or diesel fuel. In one aspect, a composition is provided that may be added to a fuel. The composition includes a fuel soluble ferrocene compound and a fuel soluble solid carrier. In some embodiments, the composition consists of only these two -25- constituents. In-other embodiments, the composition may be augmented by other constituents such as combustion additives. The composition may be useful for forming tablet dosage forms. In another aspect, a method is provided to form fuel additive tablets. In a first method, preparing the fuel additive tablet involves providing a fuel soluble 30 ferrocene compound, providing a fuel soluble solid carrier, and combining the fuel soluble ferrocene compound and fuel soluble solid carrier to form a mixture. In some embodiments, the method may also involve compressing the mixture into a tablet. In some embodiments, the method may also involve reducing the mixture to 6 WO 2007/062330 PCT/US2006/061055 a desirable particle size (conducive to compression or compaction) and compressing the mixture into a tablet. The order of any steps to carry out the process can vary and still results in an acceptable tablet. Particle sizes can range from 0.0001 mm to 3 mm. 5 In another aspect, a method is provided to form fuel additive tablets. Preparing the fuel additive tablet with this second technique involves providing a fuel soluble ferrocene compound, providing a fuel soluble solid carrier, melting the fuel soluble ferrocene compound, melting the fuel soluble solid carrier, combining the fuel soluble ferrocene compound and the fuel soluble solid carrier to form a 10 mixture or a solution, and cooling the mixture or solution to produce a solid mixture or a solid solution. In some embodiments, the method may also involve forming the mixture into a tablet. In some embodiments, the method may also involve reducing the mixture to a desired particle size such as by pulverizing, grinding, or the like, followed by compressing the mixture into a tablet. In some embodiments, the 15 cooling step is conducted in a shaped mold. The tablet forms created by the processes of the invention can be useful in improving handling of fuel soluble ferrocene compounds before mixing with a combustion fuel. The tablet forms also can be useful for enhancing dissolution in fuels more rapidly than the undiluted fuel soluble ferrocene compound itself. 20 Combustible Fuels As required by a particular process or combustor, any suitable fuel can be treated or combined with a composition described herein. For example, the fuel may be an open flame fuel or a combustion fuel, such as blends of fuels, distillate fuels, including diesel fuel, e.g., No. 2 diesel fuel, gasoline, jet fuel, e.g., Jet A, or the like, 25 and biologically-derived fuels, such as mono-alkyl ester based oxygenated fuel, i.e., fatty acid esters, triglycerides, soybean oil, Canola oil, and/or tallow. Other hydrocarbons including liquids, gases, e.g., natural gas or fuel derived from gases and/or emulsion components can be employed. Other examples of fuels include oil fired burner heating device fuels, such as kerosene, alcohols, oils, greases, and 30 asphalts. 7 WO 2007/062330 PCT/US2006/061055 Additional Fuel Additives Examples of combustion catalysts include ferrocene and its derivatives represented by the formula: Fe where each R and R' are independently selected from hydrogen, alkyl, cycloalkyl, 5 aryl, alkoxy, ketone, ester, aldehyde, amide, hydroxyalkyl, or heterocyclic. Examples include, but are not limited to, dicyclopentadienyliron, di(methylcyclo pentadienyl)iron, di(ethylcyclopentadienyl)iron, methylferrocene, ethylferrocene, propylferrocene, isopropylferroccene, n-butylferrocene, dihexylferrocene, phenylferrocene, m-tolylferrocene, didecylferrocene, dicyclohexylferrocene, and 10 dicyclopentylferrocene. Other examples include dialkylaminomethylferrocene. In some embodiments, the fuel soluble ferrocene compound may be a liquid, such as butylferrocene. In other embodiments, the fuel soluble ferrocene compound may be a solid. Carrier 15 The fuel soluble solid carrier used in the compositions and methods described herein, include those carriers which are soluble in a fuel and are sufficient to release the additive or additives into the fuel. Furthermore, the carrier may include those which, when compressed, are capable of holding its shape in combination with the fuel soluble ferrocene compound. The carrier can also be 20 compatible with mechanical elements used in burning or combusting fuels. The carrier can also be burned itself. Useful fuel soluble solid carriers include non paraffinic hydrocarbons, a single oxygen-bearing hydrocarbon, and mixtures thereof. Examples of such carriers include biphenyl, 1 -naphthol, 2-naphthol, diphenylmethane, hexadecanol, tritylalcohol, adamantane, terphenyl, p-tert 25 butylphenol, acenapthene, triphenylmethane. In some embodiments, the fuel soluble solid carrier is a single oxygen-bearing hydrocarbon such as an alcohol, ether, aldehyde, or ketone. In other embodiments, the fuel soluble solid carrier is an aromatic hydrocarbon. In some examples, the fuel soluble solid carrier is an unsaturated hydrocarbon, such as linear and branched alkenes, cycloalkenes, and 30 arylalkenes. 8 WO 2007/062330 PCT/US2006/061055 Carriers with high melting points, typically between 40 and 150 IC and which may be sparingly soluble in a fuel, are not desirable. Time release or sustained release carriers are not desirable. Waxes can compromise the bum rate of a fuel, possibly affecting engine performance in combustion applications. Waxes 5 can also serve as nucleation sites and accumulate, even occlude mechanical passageways, especially in cold climate conditions. The fuel soluble solid carrier may also be in the form a binary, ternary, etc. mixtures. These mixtures may include one or more non-paraffinic hydrocarbons, a single oxygen-bearing hydrocarbons, and mixtures thereof, such as the mixture 10 formed when using both adamantane and biphenyl. In some examples, the carrier can also serve a dual function as being another additive itself. In one aspect, the selection of fuel soluble solid carrier can be directed to maximizing the melting point of the composition while maintaining an adequate solvation in a fuel. For example, a high melting point enables the fuel soluble 15 ferrocene compound and compositions with the same to be handled in hot environments. Other additives Additional additives may be added to the compositions. One such additive can be a dye. An acceptable dye can be any dye that provides a distinctive color to 20 the composition that might allow an observer to distinguish the composition from other materials or that the composition is present in fuel. Another such additive can be a detergent/dispersant. An acceptable detergent/dispersant can be any detergent/dispersant that assist in removing residue from mechanical parts in contact with fuel. Examples include polyisobuteneamines 25 which are obtainable, according to EP-A 244 616, by hydroformylation of highly reactive polyisobutene and subsequent reductive amination with ammonia, monoamines or polyamines, such as dimethyleneaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine; (b) poly(iso)buteneamines which are obtainable by 30 chlorination of polybutenes or polyisobutenes having double bonds predominantly in the P and y position and subsequent amination with ammonia, monoamines or the abovementioned polyamines; (c) poly(iso)buteneamines which are obtainable by oxidation of double bonds in poly(iso)butenes with air or ozone to give carbonyl or 9 WO 2007/062330 PCT/US2006/061055 carboxyl compounds and subsequent amination under reducing (hydrogenating) conditions; (d) polyisobuteneamines which are obtainable, according to DE-A 196 20 262, from polyisobutene epoxides by reaction with amines and subsequent dehydration and reduction of the aminoalcohols; (e) if required, hydroxyl-containing 5 polyisobuteneamines which are obtainable, according to WO-A 97/03946, by reaction of polyisobutenes having an average degree of polymerization P of from 5 to 100 with nitrogen oxides or mixtures of nitrogen oxides and oxygen and subsequent hydrogenation of these reaction products; (f) hydroxyl-containing polyisobuteneamines which are obtainable, according to EP-A 476 485, by reaction 10 of polyisobutene epoxides with ammonia, monoamines or the abovementioned polyamines; (g) polyetheramines which are obtainable by reaction of C 2 to C 30 alkanols, C 6 to C 30 alkanediols, mono- or di- C 2 to C 30 alkylamines, CI to C 30 alkylcyclohexanols or C 1 to C 30 alkylphenols with from 1 to 30 mol of ethylene oxide and/or propylene oxide and/or butylene oxide per hydroxyl or amino group 15 and subsequent reductive amination with ammonia, monoamines or the abovementioned polyamines, it is also possible to use polyetheramines having a carbamate structure; and, (h) "polyisobutene Mannich bases" which are obtainable, according to EP-A 831 141, by reaction of polyisobutene-substituted phenols with aldehydes and monoamines or the abovementioned polyamines. Conventional 20 dispersants are, for example, imides, amides, esters and ammonium and alkali metal salts of polyisobutenesuccinic anhydrides, which are used in particular in lubricating oils, but some of which are also used as detergents in fuel compositions. Yet another additive can be an antioxidant. An acceptable antioxidant can be any antioxidant that provides protection against reaction of the fuel prior to burning. 25 - Examples include phenolic-auti6xidants;amine antioxidants, sulfurized phenolic compounds, and organic phosphites among others. Examples also include hindered phenolic compounds such as 2,6-di-tert-butylphenol, 4-methyl-2,6 ditertbutylphenol, 2,4-di-methyl-6-tert-butyl phenol, 4,4'-methylenebis(2,6-di-tert butyl phenol), and mixed methylene bridged polyalkyl phenols. Further examples 30 include aromatic amine compounds such as the cycloalkyl-di-alkyl amines and phenylenediamines. Still another additive can be a demulsifier. An acceptable demulsifier can be any demulsifier that provides to destabilize emulsions. Examples include organic 10 WO 2007/062330 PCT/US2006/061055 sulfonates, polyoxyalkylene glycols, and oxyalkylated alkylphenolic resins, and the like. Another additive can be a corrosion inhibitor. An acceptable corrosion inhibitor can be any corrosion inhibitor that retards or stops chemical reactions that 5 degrade mechanical parts in contact with a fuel. Examples include dimmer and trimer acids, such as are produced from tall oil fatty acids, oleic acid, linoleic acid, or the like. Other examples include alkenyl succinic acid and alkenyl succinic anhydride such as tetrapropenyl succinic acid, tetrapropenylsuccinic anhydride, tetradecenylsuccinic acid, tetradecenylsuccinic anhydride, hexadecenylsuccinic acid, 10 hexadecenylsuccinic anhydride, and the like. Still other examples include the half esters of alkenyl succinic acids having 8 to 24 carbon atoms in the alkenyl group with alcohols such as the polyglycols. Proportions The amount of any fuel soluble ferrocene compound and fuel soluble solid 15 carrier, as well as any other additive may vary depending upon the needs and conditions associated with the fuel and its use. Generally, the additives may be blended or otherwise mixed at any suitable ratio to give a desired release rate when the composition is placed in contact with a fuel. Typically, ratios of fuel soluble ferrocene compound to fuel soluble solid carrier can be at a ratio of from about 9:1 20 to about 1:500. In some examples, the ratio of fuel soluble ferrocene compound to carrier is from about 1:50 to about 1:10. A test to determine the visual clarity (a measure of solubility) of the composition in a fuel involves addition of 0.3 g to 1.0 g of a pelletized material to a glass vessel and visual observation as to whether solid particles are present after a specified period of time, for example, 30 minutes. 25 The relative proportion of the fuel additive in the composition may be expressed in terms of weight percent. In some embodiments, the composition includes less than about 90% fuel soluble ferrocene compound. In other embodiments, the composition includes less than about 70% fuel soluble ferrocene compound. In still other embodiments, the composition includes less than about 30 50% fuel soluble ferrocene compound. In other embodiments, the composition includes less than about 30% fuel soluble ferrocene compound. In other embodiments, the composition includes less than 15% fuel soluble ferrocene compound. In other embodiments, the composition includes less than 10% fuel 11 WO 2007/062330 PCT/US2006/061055 soluble ferrocene compound. In other embodiments, the composition includes less than 7% fuel soluble ferrocene compound. In other embodiments, the composition includes less than 5% fuel soluble ferrocene compound. In other embodiments, the composition includes less than about 3% fuel soluble ferrocene compound. In other 5 embodiments, the composition includes less than about 1% fuel soluble ferrocene compound. The relative proportion of the fuel soluble ferrocene compound once dissolved in a fuel stream can vary. In some embodiments, the amount of fuel soluble ferrocene compound is less than about 1000 ppm. In other embodiments, the 10 amount of fuel soluble ferrocene compound is less than about 650 ppm. In other embodiments, the amount of fuel soluble ferrocene compound is less than about 450 ppm. In other embodiments, the amount of fuel soluble ferrocene compound is less than about 250 ppm. In other embodiments, the amount of fuel soluble ferrocene compound is less than about 100 ppm. In other embodiments, the amount of fuel 15 soluble ferrocene compound is less than about 50 ppm. In other embodiments, the amount of fuel soluble ferrocene compound is between about 10 and about 30 ppm. Solvation In another aspect, the compositions including a fuel soluble ferrocene compound and fuel soluble solid carrier improve solvation rates compared to the 20 fuel soluble ferrocene compound alone or when compared to time release or sustained release materials. Rapid solvation may be desirable when fueling a vehicle, or other combustion engine for homogeneous blending of the fuel soluble ferrocene compound and/or other additive. In some embodiments, the composition can substantially dissolve within 60 minutes. In other embodiments, the 25-- composition can substantially dissolve within 30 minutes.- In other embodiments, the composition can substantially dissolve within 15 minutes. In other embodiments, the composition can substantially dissolve within 12 minutes. In other embodiments, the composition can substantially dissolve within 10 minutes. In additional embodiments, the composition can substantially dissolve within 7 30 minutes. In other embodiments, the composition can substantially dissolve within 5 minutes. In other embodiments, the composition can substantially dissolve within 3 minutes. 12 WO 2007/062330 PCT/US2006/061055 In still another aspect, methods of supplementing a fuel or are disclosed. Fuel supplementation may occur by solvating the combustion additive, the combustion additive comprising a fuel additive composition to the fuel, the fuel additive composition comprising a fuel soluble ferrocene compound and a fuel 5 soluble solid carrier. In some embodiments, the fuel supplementation may occur when an end user inserts one or more tablets or other forms of the composition into a fuel tank and the composition dissolves, i.e. solvates within a fuel tank. In other embodiments, the fuel supplementation may occur when a fuel producer adds one or more tablets or 10 other forms of the composition into a blending tank with the fuel. The solvated and blended fuel composition then includes the fuel and the fuel soluble ferrocene compound . Such an embodiment may be useful before distributing the fuel to end users. 15 EXAMPLES The present invention is illustrated by the following Examples. It is to be understood, however, that the instant Examples are offered by way of illustration of the invention and are not to be construed in any manner as limitations thereof. It is also to be understood that, where designated, some examples are prophetic. 20 Example 1 In a container, 0.22 g of ferrocene and 2 g of biphenyl were added and heated to approximately 70 0 C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet 25 - weighed approximately-one-half gram. Example 2 In a container, 0.22 g of ferrocene and 2 g of 1 -naphthol were added and heated to approximately 95 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room 30 temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 0.3 g. 13 WO 2007/062330 PCT/US2006/061055 Example 3 In a container, 0.3 g of ferrocene, 1.8 g of hexadecanol, and 1.8 g of adamantane were added and heated to approximately 90 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped 5 molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 1.1 g. Example 4 In a container, 0.27 g of ferrocene, 2.0 g of hexadecanol, and 1.0 g of adamantane were added and heated to approximately 80 'C. The mixture was 10 stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 0.5 g. Example 5 In a container, 0.25 g of ferrocene, 1.6 g of biphenyl, and 1.9 g of 15 triphenylmethanol were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 0.6 g. Example 6 20 In a container, 0.35 g of ferrocene, 2.7 g of biphenyl, and 0.3 g of triphenylmethanol were added and heated to approximately 90 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 0.5 g. 25 Example 7 In a container, 0.68 g of ferrocene, 2.7 g of biphenyl, and 0.3 g of triphenylmethanol were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped 30 material was removed and each pellet weighed approximately 0.8 g. Example 8 In a container, 0.44 g of ferrocene and 8.8 g of acenaphtene were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot 14 WO 2007/062330 PCT/US2006/061055 solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 2.1 g. Example 9 5 In a container, 0.54 g of ferrocene and 10.4 g of butylphenol were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 2.2 g. 10 Example 10 In a container, 0.46 g of ferrocene and 9.2 g of terphenyl were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet 15 weighed approximately 2.0 g. Example 11 In a container, 0.64 g of ferrocene and 12.7 g of biphenyl were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room 20 temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 1.9 g. Example 12 In a container, 0.59 g of ferrocene, 0.4 g of acenapthene, and 1.1 g of butylphenol were added and heated to approximately 80 'C. The mixture was 25 stirred until dissolution. The-hot solution-was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 2.2 g. Example 13 In a container, 0.5 g of ferrocene, 0.87 g of butylphenol, and 8.8 g of 30 terphenyl were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 2.2 g. 15 WO 2007/062330 PCT/US2006/061055 Example 14 In a container, 0.49 g of ferrocene, 1.1 g of terphenyl, and 8.6 g of biphenyl were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and 5 allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 2.1 g. Example 15 In a container, 1.3 g of ferrocene and 18.7 g of biphenyl were added and heated to approximately 75 'C. The mixture was stirred until dissolution. The hot 10 solution was poured into ceramic, pellet-shaped molds and allowed to cool to room temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 2.1 g. Example 16 In a container, 1.3 g of ferrocene and 18.7 g of biphenyl were added and 15 heated to approximately 75 'C. The mixture was stirred until dissolution. The hot solution was cooled to room temperature. Solid was pulverized to a fine powder. Some of this power was compressed into tablets containing approximately 1000 mg total weight. Example 17 20 In a container, 5 g of ferrocene and 78 g biphenyl were added and heated to approximately 75 'C. The mixture was stirred until dissolution. The hot solution was poured into agitated cold water (500 mL). Solid was filtered, dried and pulverized to a fine powder. Some of this powder was compressed into tablets containing approximately 1000 mg total weight. 25 -Example 18 In a container, 0.30 kg of ferrocene and 4.8 g of biphenyl were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into 5 gal. agitated cold water. The solid was filtered, dried and pulverized to a fine powder. This powder was compressed into about 6000 tablets 30 containing approximately 800 mg total weight Example 19 In a mortar, 1.3 g of ferrocene and 18.7 g of biphenyl were added, followed by pulverizing and mixing the components into a fine powder. The resulting powder 16 WO 2007/062330 PCT/US2006/061055 was poured into pellet-shaped molds and compressed. After compression, the pellet shaped material was removed and each pellet weighed approximately one gram. Comparative Examples Example 20 5 An additional comparative example 20 was examined. A one gram tablet of ferrocene was obtained from Chemplex Automotive Group, Inc., Fullerton California. The tablet was added to 500 mL of gasoline. Approximately half of the table was observed to dissolve after 60 minutes. Therefore, it was observed a 1 gram tablet of ferrocene itself does not dissolve in less than 60 minutes. 10 Example 21 An additional comparative example 21 was examined. In a container, 0.26 g of ferrocene, 1.4 g of hexadecanol, and 1.4 g of wax were added and heated to approximately 80 'C. The mixture was stirred until dissolution. The hot solution was poured into ceramic, pellet-shaped molds and allowed to cool to room 15 temperature. After cooling, the pellet-shaped material was removed and each pellet weighed approximately 0.4 g. Prophetic Examples Example 22 In a container, 0.22 g of acetylferrocene can be added with 2 g of biphenyl 20 then heated to approximately 70 0 C. This mixture can be stirred until dissolution. The hot solution can be poured into ceramic molds giving 4 solid pellets of approximately one-half gram each. Example 23 In a container, 0.22 g of ethylferrocene can be added with 2 g of biphenyl 25 then heated to approximately 70 C. This mixture can be stirred until dissolution. The hot solution can be poured into ceramic molds giving 4 solid pellets of approximately one-half gram each. Example 24 In a container, a volume of butylferrocene constituting 5% by weight can be 30 added with a mass of biphenyl constituting 95% by weight. The combination can then be heated to approximately 70 1C. The hot solution can be poured into ceramic molds giving solid pellets of approximately one-half gram each. Alternatively, the hot solution can cooled and the material pulverized for compaction into a pellet. 17 WO 2007/062330 PCT/US2006/061055 Solvation Studies Pellets from each of the above-described examples were studies for time of solvation in gasoline. Gasoline was obtained from a gas station in Utah during a summer month. A single sample pellet was then added to 500 mL of gasoline and 5 observed until the tablet was dissolved. Table I displays the time observed for complete solvation of the pellet. Pellets were of various sizes from less than one gram to more than one gram. Table I Solid Pellets: Time to dissove in 500 mL of gasoline Pellet from Example 1 2 min 20 sec Pellet from Example 2 ~30 min Pellet from Example 3 6 min 30 see Pellet from Example 4 3 min 50 see Pellet from Example 5 -6 min Pellet from Example 6 3 min 20 sec Pellet from Example 7 2 min 45 sec Pellet from Example 8 7 min Pellet from Example 9 21 min Pellet from Example 10 10 min 40 sec Pellet from Example 11 3 min 25 sec Pellet from Example 12 6 min Pellet from Example 13 10 min Pellet from Example 14 3 min 10 sec Pellet from Example 15 3 min Pellet from Example 16 4 min Pellet from Example 17 6 min Pellet from Example 18 6 min Pellet from Example 19 4 min 10 sec Pellet from Example 20 > 60 minutes Pellet from Example 21 ~50 min Melting point study 10 Melting points were observed for various combinations of a composition involving ferrocene and biphenyl. Table II provides summary of the observations where the composition is expressed as a percent by weight of ferrocene and the balance being biphenyl. Melting points were determined using a Mel-temp capillary melting point apparatus. Both start and end points are reported in the table. 18 WO 2007/062330 PCT/US2006/061055 Table II % errcn Meltng point C start Melting point 'C finish 0 68.2 69.9 4.8 63.8 67.2 6.5 62.8 66.4 9.9 60.6 64.4 15.1 60.3 62.7 20.8 59.7 60.8 25.2 59.9 76.6 50.2 60.2 126.7 100 172.9 174.2 While the invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced with the scope of the following claims. 19

Claims

1. A composition comprising: (a) a fuel soluble ferrocene compound; and 5 (b) a fuel soluble solid carrier which is biphenyl.

2. The composition according to claim 1, wherein the fuel soluble ferrocene compound is selected from one or more compounds of the formula: 11 R Fe wherein each of R and R' are independently selected from hydrogen, alkyl, cycloalkyl, aryl, [0 alkylene, alkoxy, ketone, ester, aldehyde, amide, hydroxyalkyl, or heterocyclic.

3. The composition according to any one of claims 1 or 2, wherein the fuel soluble ferrocene compound is unsubstituted ferrocene.

4. The composition according to any one of claims 1 or 2, wherein the fuel soluble ferrocene compound is a substituted ferrocene. 15

5. The composition according to any one of claims I to 4 further comprising one or more additional fuel soluble ferrocene compounds.

6. The composition of any one of claims 1 to 5, wherein the composition is in the form of a tablet.

7. A method of preparing a fuel additive comprising: combining a fuel soluble ferrocene 20 compound and biphenyl.

8. The method according to claim 7, further comprising: adding a second fuel soluble ferrocene compound to the fuel additive. 20

9. The method according to claim 7, wherein the fuel soluble ferrocene compound is selected from one or more of ferrocene and ferrocene derivatives.

10. The method according to any one of claims 7 to 9, further comprising: melting the fuel soluble ferrocene compound; melting biphenyl; mixing the fuel soluble ferrocene compound and 5 biphenyl to form a mixture.

11. The method according to any one of claims 7 to 10, further comprising: forming a tablet.

12. A method of supplementing a fuel comprising: adding a fuel additive composition as claimed in any one of claims 1 to 6 to the fuel.

13. A composition according to claim 1, substantially as hereinbefore described with 10 reference to any one of the examples.

14. A method according to claim 7, substantially as hereinbefore described with reference to any one of the examples. 21